Manufacture of wallboard



Aug. 17, 1937. l C. o. WALPER 2,090,084

MANUFACTURE 0F wALLBoARD Filed June 1, 1955 zsheefs-sheet 1 l NVE NTOR= CURRV ORA WALPER ATTORNEX Ang. 17, 10937. o, WALPER Y Y 2,090,084

MANUFAGTURE OF wALLBoARD Filed June l, V1935 2 sheets-sheet 2 Fig m M ,By

ATTORNEY Patented Aug. 1?',r 1937 2,090,084

UNITED STATES PATENT OFFICE Y 2,090,084 I l MANUFAc'rUnE or wn'unoann Y Curry Ora Walper, Hamilton, Ontario,

' Canada Application June 1, 1935, Serial No. 24,461 i i 1 claim. (ci. 'isi-2i' This invention relates to the manufacture of adjustable supporting structure is provided for wallboard wherein a core of hydrated calcined this purpose; This structure comprises a series gypsum is molded and allowed to-harden withof relatively short rolls Il, each "mounted in in paper liners, one `of which folds over and bearings I2 movably supported on cams I3.withencloses the edges ofthe core, and is particuin the guide members I4 and I5 of theframe 5 larly directed to lche formation of a slightly bev- I6, which is provided for each roll. This struc elled edge on the under surface of the board at ture' is located at each side of the belt 'I at the longitudinal marginal edges of the board. spaced points along-the belt for Va-suilicient dis- A gypsum wallboard with such an edge makes tance to sustain the bevelled edge until thecore it possible to form with relative ease a greatly and adhesive have adequately setanddried to 10 improved joint between the boards when they cause -the board to retain its shape.' The twp are erected to form wall surfaces to which decpair of cams I3 in the supporting structure on oration may be applied. While it has heretoimmediately opposite sides of the belt are mountfore been proposed to bevel the edges of such ed on a shaft Il which may be reciprocated by boards, no adequate method or means have been a `handle I8. A gear or sprocketwheel I9 is i5 disclosed for forming such an edge in practice. mounted on one end of each ofY these shafts and It is to be noted that fout a slight bevel is rea belt or chain passes over these wheels to quired but to serve the purpose the bevel must Vreciprocate the shafts l1 and move all the cams be uniform and regular throughout its length I3 in unison. As mounted in the frame each 20 and width in order to receive the joint ller and roll is inclined, as shown, to conform with the 20' avoid the formation of shadow-'forming ridges bevelof the marginal edges of the board.

or projections on the nished wall surface. As illustrated in Figure 2, the rolls ll are posi- The invention will be described with referencetioned for making a relatively narrow board, to the accompanying drawings, in which say 32 inch instead of I8 inch. When the cam Fig. 1 isv a side elevation of. pertinent porshaft is reciprocated the cams revolve to low- 25*A tions of one form of apparatus for making the er the rolls, so that the inclined 'marginal por-` board. tions of the belt are much narrower and just Figure 2 iS a Section, partially broken away; sufficient to engage the bevels on theywider board,` on line 2--2 of Figure 1. the' remaining portion of the belt lying horizon- Figure 3 iS 9' Section, partially broken away, tally in engagement with the flat body portion of 30 on line 3-3 of Figure l. the board.

Figure 4 is a transverse section of the board.l 'Ihis supporting structure provides flexibility Figure 5 is a side elevation of another form and ease of adjustment for vvaryin'gzwidths of 0f apparatus, and board.

Figure 6 is a section on line 6 6 of Figure 5.v In operation the plates 5 are adjusted to deflect 35 In the drawings, I-and 2 indicate what are the margins of the belt upwardlytoform .the -llSllally knOWn aS the Squeeze T0115 which Shape desired bevels on theedges of the board.v The the COIeWithiD the paper liners 3 and 4, the latedge supporting structure is arranged-to engage ter cf which is usually folded over tc enclose the portions of tnebeu: immediately beneath the 4o the edge of the core. At the upper edge of the bevelled edges of the board and whenso arranged 40 ends of roll 2 in Flgurel is arranged a plate 5 the rolls smaintain the .margins of thebelt 1n which forms a tapered depression or bevel 6' on contact with the inclined edges of the'board until the longitudinal margins ofthe board 6. the board has become sufficiently hardened. to The usual suvpcingbelt 'I on which the beard retain its form. In other respects the operation is carried is Vmounted on driving rolls 8, 011e follows the usual procedure and does notrequire 45 only of which is shown, and th'e intermediate detailed description here.

rolls 9. Y In the simplified vform of the apparatus shown When the tapered depression or lbevel 6 isin Figures 5 and 6 there is adjustably mounted formed by the plate 5 on the lower'squeeze roll, on the belt supporting-rolls Sicollars 20 having the core is quite plastic and in order to mainthe tapered portions 2| which upwardly incline 50 tain the bevel 0l' tapered BPIBSSOD in its Origithe margins of the belt 1. The position of the nal shape until the core sets and the adhesive collars on the rolls may be adjusted by a set vscrew between the margins of the paper liners dries, the 22 or other suitable means to provide for different margins of the supporting belt must be made 'widths of board.

to conform with the bevels on the board, ,and an In operation of this form of the 'apparatus 55 the board as formed in the squeeze rolls has square or untapered edges. When the board reaches the zone of the supporting rolls it is still plastic and the upwardly inclined edges of the 5 belt form the slight taper on the under side of the longitudinal margins of the board. The belt is retained in this position for a suillcient length of time to permit the board to harden sutllcientlyto retain the slight beve 'I'his is accomplished v 10 by arranging the tapered collars on a sumcient number of the rolls and thenurnber will depend to some extent at least upon the speed of travel of the belt and the setting character of the core ot the board. As the board sets the tapered mar- 15 gins require less support and the collarsmay be arranged" progressively nearer the ends of the roll affording progressively less support for the tapered margins.

-It will be apparent that the usual scoring devices for the lower liner will be arranged closer together in or'der to accommodate the decreased thickness ofcore at the edge of the board according to the extent of the taper.

I claim: ,v In the manufacture of wallboard having a quick-setting core and e'nclosing paper liners adhering thereto the method which comprises forming a square edge board between squeeze rolls'l and thereafter while the core is in plastic condition forming a taper on the longitudinal margins of the board and maintaining the taper until the core hardens.

CURRY ORA WALPER. 

